Effect of electric potential on hydrogen adsorption over activated carbon separated by dielectric TiO2 nanoparticles

► H2 adsorption over TiO2-coated activated carbon under electric field was studied. ► Adsorption enhancement increased with increasing amount of TiO2. ► Dielectric TiO2 holds more charges in each carbon particle with applied potential. ► Electrostatic force between H2 molecule and adsorbent can be built due to charges.